Build Your Own LED Grow Light

[Amy Gardner]

Can you guys elaborate on that a bit. I’ve read in lots of places that more boards run softer is the most effective, not just for efficiency but for the way the plant gets light. I’m still learning about it all so I’d like to understand what you’re talking about a bit better

 

[Chris Scorpio]

Can you guys elaborate on that a bit. I’ve read in lots of places that more boards run softer is the most effective, not just for efficiency but for the way the plant gets light. I’m still learning about it all so I’d like to understand what you’re talking about a bit better

Meaning what Amy??

80% vs 100% power????

 

[Chris Scorpio]

They say the bds or I'd assume the diods, perform best, usage of watts to light output, at like 80-85% power

But, I do like, case in point, adding my two light brd to some lower plants in my tent, and cranking the power up to 100%

As Spinal Tap says
See all the dials go to 11, 11,11,11
Is that higher than 10?
Well yes, those blokes will be at 10, and If we need that little Xtra, what do we do
Turn it to 11
Exactly

 

[Chris Scorpio]

But why don't you make 10 loudest , make 10 the top number and make that louder
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But these go to 11


Lol

 

[TheMadDabber]

So anyone have an idea of why a led puck (small round pcb) would flicker? Is that an indication of a shortage or bad connection? One is like a stone light the other just kinda dims randomly. Asking for a friend... I noticed it happening in their store the other day

 

[Pennywise]

Bad driver maybe.

 

[TheMadDabber]

Bad driver maybe.

That's what I was thinking only the bathroom light does it. And the one other in the showroom doesnt flucker but I notice a variation in its brightness

 

[Pennywise]

Not sure, if it was a short it would pop something

 

[Amy Gardner]

Meaning what Amy??

80% vs 100% power????

They say the bds or I'd assume the diods, perform best, usage of watts to light output, at like 80-85% power

But, I do like, case in point, adding my two light brd to some lower plants in my tent, and cranking the power up to 100%

As Spinal Tap says
See all the dials go to 11, 11,11,11
Is that higher than 10?
Well yes, those blokes will be at 10, and If we need that little Xtra, what do we do
Turn it to 11
Exactly

But why don't you make 10 loudest , make 10 the top number and make that louder
.
.
.
.
.
But these go to 11


Lol

Thanks Chris - I’m just trying to learn something more about it

I have a 5 boards that are 20-60watt, .48-1.2A.

How do you calculate the percentage? Is it that running them at 40watts per board would mean they’re running at 50%?

Or is it the amps that determine the percentage of how hard they’re being driven? - so with a 700ma driver they’re at just over 50%

Or is it some equation between the 2 (the ma of the driver and how many watts you push through it) that you’d use to work it out?

 

[PurpleGunRack]

I think you've got Volt and Watt mixed up @Amy Gardner

Watt is the energy used in Joule per second, you multiply Volt and Ampere to get Watt, but this is the Watt going into the unit, not the Watt you draw from the wall, the driver takes a cut of the power to convert the AC input to DC output.

Any board/strip/COB has a max volt and ampere rating, that's 100%, if your driver can power the unit above 100% you can fry it if you're not careful.
However, some units max rating are sometimes set low and the unit can actually take more than max.

To accurately find the percentage the unit is driven at you have to know/measure the V and A.
You usually know one of the two since it's the max on your driver.

Or you can estimate the percentage based on the driver V and A output, but you have to have an idea of how things work in real life to be accurate.

To get AC draw in watts you multiply V with A and multiply with 1+ driver inefficiency.
V*A*1,xx = Watt AC (if a driver is 94% energy efficient, you multiply with 1,06)

If you use a CC driver with much lower A than the unit powered is rated for, the V will be lower than max of the unit and maybe even lower than nominal.

Type A CV drivers can go higher in V than their B counterparts, so the V is higher than nominal and the driver can go above the wattage rating you see in the specs you see on TME, Mouser etc.

 

[Amy Gardner]

Ok this is really great thanks _ i don’t have watts and amps mixed up exactly, I only was missing that there are 2 differnt ways watts come into the picture. One is the watts coming frm the wall (which I can measure with the killwat type meter) and the other is what you refer to there as the watt going into the unit - I had thought these were the same thing (or that they correspond). So that’s where I’ve been missing something.

So my boards are 48V, .48 - 1.2A and the board specs also list them as being 20 -60 watt (this is from the manufacturer).

The driver is 185H-C700, so constant current with max 700mA output, a maximum output voltage of 286V, and rated at 200.2watts - so I understand the basics well enough to know that’s not going to fry my boards (at least I think I do! ).

What I was wondering about above was 2 things really (kind of related). One was how do I work out how hard I should drive them for my space. So your help is appreciated - I’m trying to get my head around it.

(The other thing - was wondering about what Chris was talking about with driving them... because I don’t really understand things well enough to get why going for the efficiency is not a good idea in terms of light, and i wanted to understand it better. I may never though at this rate )

But back to driving my light and the info you’re sharing there:

To accurately find the percentage the unit is driven at you have to know/measure the V and A.
You usually know one of the two since it's the max on your driver

So is it right then to say that wth my driver at 100% full (it’s the A version with the built in dimmer), I’m driving the boards at a bit over 50%? As far amperage goes...? Or am I still looking at that wrong?

To get AC draw in watts you multiply V with A and multiply with 1+ driver inefficiency.
V*A*1,xx = Watt AC (if a driver is 94% energy efficient, you multiply with 1,06)

Few questions about that... are you talking about the V and A of teh driver or the boards there? How do I know how efficient the driver is? And is that meant to be a comma? (This is about where my brain begins to fry )

I appreciate the help PGR. I knew nothing at all 6 months ago and have earned enough to understand most of the basics (differences in divers and and wiring etc.). I then had really good advice from Gray when building my kit, which was awesome (and easier for me than a conversation with many in a thread) and now I am trying to get my head around the next level of knowledge - and be able to work out how to drive the boards to get the level of light my space needs (2.5x2.5 grow footprint).

 

[Chris Scorpio]

Couple things

Get a watt meter, something like this

Then u know exact watts yer at

Your 185h-c700, gives you ruffly 185w max output and 700ma max

My 320h-c2100b maxes at ruffly 320w and 2100ma
My bds, each are 75w and 2000ma, so I can run 4 at 100% output
Now my 1st driver was a 240h-c1750b, I could only get about 80% output on two bds, what!!!! It was because the bds max at 2000ma and my driver maxed at 1750ma

So, if your bds rate at say 1200ma, your driver will never max out, or even close.
And if your bds do 60w, and you have 4, again, your 185h cant do max watts either

That make sense

 

[PurpleGunRack]

i don’t have watts and amps mixed up exactl

Not watt and ampere - VOLT and watt , forget about watt for awhile and focus on volt and ampere

Volt and Ampere is what we put in our unit(s), and watt is what we pay to put the V and A in.

The driver is 185H-C700, so constant current with max 700mA output, a maximum output voltage of 286V, and rated at 200.2watts - so I understand the basics well enough to know that’s not going to fry my boards (at least I think I do! ).

Output voltage: 143...286V DC - Your units' combined voltage has to be in this range for it to work.

Output current: 350...700mA

Efficiency: 94%


You can adjust the ampere, and the volt is automatically matched with the current, so you can't just assume that your boards get 48V each, it might be 46V or lower at 0,7 ampere

Your boards 5*48V = 240v
And 1,2 ampere, so you can't come close to overpowering your 5 boards.

To estimate percentage of max rating: 700 mA / 1200 mA = 0,58333333 -> 58,3% of max, but in reality it's lower because the voltage is probably a bit lower.

To estimate AC draw: 0,7A * 240V = 168w DC x 1,06 = 178,08w AC, and probably a bit lower in reality, my guess is 167w

What I was wondering about above was 2 things really (kind of related). One was how do I work out how hard I should drive them for my space. So your help is appreciated - I’m trying to get my head around it.

General advice is 50-75%, but I'd recommend having a driver that can power the units at at least 75% of max, the price difference when going up a size in driver is marginal.
But if the driver can give you more than 100% of max you have to hook up a multimeter when adjusting the output.

How hard you should drive them depends on the number of diodes, what stage in the cycle the plants are in and what you want to achieve.

Rule of thumb is 800 diodes per m2 (10,8 sq. ft.) 464 diodes in your case (running at 75% of max in flower)
Another rule of thumb is 30w per sq. ft., but that's too vague a rule in my opinion.

(The other thing - was wondering about what Chris was talking about with driving them... because I don’t really understand things well enough to get why going for the efficiency is not a good idea in terms of light, and i wanted to understand it better. I may never though at this rate )

The rule of thumb of more units running softer applies to COBs, not to middle power diodes.
You want to run middle power diodes at 50-75% of max to get a good mix of output and efficiency, running them too soft gives you very little penetration power and you have to do ScroG to get some proper bud.

Personally I think 50% is too weak for flowering(with 800 diodes/m2), so I usually go for 70-80%

50% of a HLG driver's max is usually where it drops below 90% efficiency

Few questions about that... are you talking about the V and A of teh driver or the boards there? How do I know how efficient the driver is? And is that meant to be a comma? (This is about where my brain begins to fry )

I'm talking about the actual V and A going into the unit(s), not the min/nominal/max ratings of either.

It's in the specs for the driver, keep in mind that dimming lowers the efficiency which there should be a graph for in the data sheet.

It's a decimal seperator, visualize a point if you like




Hope that clarifies it a bit, I know it's hard to learn from text, being a learning by doing person myself

 

[Mayne]

PGR, I personally also want to thanks you for taking time to write out allllll kinds of information for people to learn this industry.

Im sure I speak for everyone,

SO,

Thanks Man,,,,

 

[Amy Gardner]

Not watt and ampere - VOLT and watt , forget about watt for awhile and focus on volt and ampere

Ok - I get that, I really do...

I was responding to you saying this

I think you've got Volt and Watt mixed up @Amy Gardner

Except I typed ‘amp’ instead of ‘volt’

So I get volts and amps and their differences (and watts) - it was the first thing I learnt about. It just doesn’t always come out the way it’s in my head! Any hoo - Now I’m trying to understand their relationship as it relates to my setup.

This would be so much easier in conversation!

I’ll go back over the last 2 posts and come back with how I understand it - or not ...

@Chris Scorpio thanks you too yes that all made sense to me (phew!). My 185driver actually pumps 200watts, not much more but a little.

Hope that clarifies it a bit, I know it's hard to learn from text, being a learning by doing person myself

it really does! I’m a learning by talking and doing, so I find learning technical stuff via the forums like this super challenging. But I figured I’d reached a point that it’d be ok. I’m borderline right now but will get there I think...


Thansk both - I’ll spend some time with that info

 

[DrDoob]

A few months ago I randomly bought 4 HLG QB132 Quantum Boards and a HLG-185H-C1400B not totally sure why I bought this combo but I’m sure I read it was good somewhere.

I don’t know the difference between a watt and an amp, but I think these lights could support up to 300w and this power supply only supports up to 200w. So I think I can’t really crank it to up 11 but am running efficiently? It seems like plenty of light for my 2’x2’ tent so I’m happy, just wish I could do math.

I made the frame from some used openbeam kit I found out in the garage. It’s about as Frankenstein as it gets but seems to be functional.

 

[Amy Gardner]

Rule of thumb is 800 diodes per m2 (10,8 sq. ft.) 464 diodes in your case (running at 75% of max in flower)
Another rule of thumb is 30w per sq. ft., but that's too vague a rule in my opinion.

excellent- I have 640 diodes! So that’s plenty. Seems I should maybe be driving them harder, ive been dimming it a bit which means they’re likely running under 50% right now (still in veg).

Thansk PGR that all makes sense. Gonna take a bit of time but I’m getting there...

To estimate AC draw: 0,7A * 240V = 168w DC x 1,06 = 178,08w AC, and probably a bit lower in reality, my guess is 167w

The watt meter reads 186 with the driver on full - but as this is draw from the wall I need to work out how that translates to power at the boards so I can use it to adjust things. I think I can do that with the info above. If not I’m just going to come back and request someone do yeh math for me!

 

[Amy Gardner]

Get a watt meter, something like this

Yep! I have one. Have been using it to monitor dimming the driver (it’s currently plugged in permanently).

So that was part of my question that I think PGR pointed out I had a bit wrong...
the meter shows me draw from the wall, right? What I’m trying to figure out is how that translates to how much power (in watts) each of the boards is getting. Therefore, how do I use that meter to gauge and manipulate the light output.

I think what PGR has written above can help me do that. Once I study it some more.

Oh and what PGR put there about optimum being 50-75% also helps me understand why you were rejecting going too far down the efficiency side of things.

 

[Chris Scorpio]

Yep! I have one. Have been using it to monitor dimming the driver (it’s currently plugged in permanently).

So that was part of my question that I think PGR pointed out I had a bit wrong...
the meter shows me draw from the wall, right? What I’m trying to figure out is how that translates to how much power (in watts) each of the boards is getting. Therefore, how do I use that meter to gauge and manipulate the light output.

I think what PGR has written above can help me do that. Once I study it some more.

Oh and what PGR put there about optimum being 50-75% also helps me understand why you were rejecting going too far down the efficiency side of things.

That's easy

If you have 4 bds, that can max at at 60w/bd so that's 240w max they can run at, ish

And yer meter says yer running at 175w currently

175/240 = 72.9% of theoretically max

 

[nivek]

Back later. Cheers